DESCRIPTION: (Applicant's abstract) The long term goal of this proposal is to develop a simple blood-based assay for the early diagnosis of myocardial ischemia. lschemic heart disease is the major cause of death in the United States. Current methods of diagnosis are either unreliable or complex and expensive. Cardiac marker assays reliably detect necrosis but not ischemia per se. In contrast, the diagnostic method we propose, the measurement of serum unbound FFA (FFAu), involves a simple, inexpensive, virtually instantaneous, and readily accessible measurement that has high potential for revealing the ischemic event. In the proposed Phase I studies we will determine if plasma FFAu levels, measured with our ADIFAB fluorescence method, provide an early indicator of cardiac ischemia in the rat. If, as we expect from preliminary studies, plasma levels of FFAu rise to very high levels within minutes following the ischemic insult, then we should be able to use the rat model to help define the characteristics of this assay in preparation for a Phase II trial in human patients. PROPOSED COMMERCIAL APPLICATION: If successful this research would demonstrate that unbound free fatty acids (FFAu) provide the earliest and most sensitive blood-assay based measure of myocardial ischemia. If supported by subsequent phase II and III trials, we would expect, in conjunction with a small, inexpensive single purpose fluorometer, that this assay would be used to provide the earliest indication of myocardial ischemia. This assay is based on our patented method which is the only reported method for measuring FFAu, thereby ensuring considerable commercial application.